I used to feel the same, where I'd get hit the hardest. As a kid I caught everything that ever went around, and there were a couple years where teachers debated on letting me advance a grade because I missed too many days from being sick. But I've only had the flu once in my life (and of course it had to be the swine flu!) A few years ago I took an Allergra every day, not just for allergies, but for colds. I haven't caught a cold or a sickness in the last year, and I'm not taking any meds anymore. Meanwhile, my brother (who lives with my husband and I) gets sick every other week. I think I haven't caught anything because I'm on a really strict clean diet, I get chiropractic adjustments 3 times a month, and I'm on loads of herbs and supplements from my naturopath. I'm really coming to believe that the more toxins in our body, the more easily we get sick.